AB0604 Influence of the location and severity of vascular involvement on the basal phenotypic expression and on the evolution of giant cell arteritis
Authors: A. Ginon, M. D. C. Uyaguari Morocho, E. Fernández-Fernández, I. Monjo, E. de Miguel
Journal: Annals of the Rheumatic Diseases (2022)

Background Giant cell arteritis (GCA) is the most common systemic vasculitis in adults. There is increasing evidence about clinical subtypes of the disease depending on the cranial or extracranial vessels involvement. However, how this type of affectation influences the phenotypic expression of the disease and whether there are differences between them in terms of the thickness of the vessels wall, are still aspects that remain to be clarified. Objectives To evaluate the association between the subtypes of GCA and the basal phenotypic expression and severity of the artery walls affectation in the disease. Methods This is a retrospective study of new consecutive patients diagnosed with GCA in our hospital from July 2018 to December 2020. The patients underwent Color Doppler ultrasound at the time of diagnosis of cranial arteries (superficial temporal arteries in the common superficial temporal artery and their frontal and parietal branches) and extra-cranial arteries (axillary, subclavian, and carotid arteries). The ultrasound diagnosis was made according to the OMERACT definitions of the halo sign and cut-off the intima media thickness was established as ≥0.34 mm for the branches of the temporal arteries, ≥0.42 in the common superficial temporal artery and ≥1 mm for the axillary, subclavian, and carotid arteries. The “halo score” (HScore) was calculated according to the criteria published by Van der Geest KSM et al. 1 In addition, the clinical records of the patients were reviewed and their demographic, clinical and laboratory data were compared between the different sonographic subtypes of GCA. A p &lt; 0.05 limit of statistical significance was established. The Statistical analysis was performed using SPSS version 25. Results A total of 74 patients were included, of which 44 (58.7%) were women with a mean age of 78.6 ± 8.6 years. Analyzing the GCA subtypes: 18 (24.3%) had exclusively cranial involvement (CGCA), 12 (16.2%) patients had GCA of extra-cranial large vessels (LVGCA) and 44 (59.5%) patients had mixed forms cranial and extra-cranial (MGCA). The characteristics of the population and of each of the GCA subtypes, as well as thickening of the wall of the arteries are described in Table 1. Table 1. Clinical characteristics of the study population. Conclusion The constitutional syndrome was always present in LVGCA but it is also very common in subtypes with cranial involvement. The ischemic syndrome occurs preferentially in groups with cranial vessel involvement, but not exclusively. The thickening of the arterial wall of the cranial arteries shows no difference between CGCA and MGCA; and the same occurs in the large vessels between the LVGCA and the MGCA. Serious adverse effects due to ischemia showed a similar risk regardless of whether it was CGCA or MGCA. References [1]van der Geest KSM., Borg F., Kayani A., et al. Novel ultrasonographic Halo Score for giant cell arteritis: assessment of diagnostic accuracy and association with ocular ischaemia. Ann Rheum Dis. 2020;79:393–9. Disclosure of Interests None declared